Concept Guide

Data Center Bridging (DCB)
Topics:
• Enabling Data Center Bridging
• Ethernet Enhancements in Data Center Bridging
• QoS dot1p Trac Classication and Queue Assignment
• SNMP Support for PFC and Buer Statistics Tracking
• DCB Maps and its Attributes
• Data Center Bridging: Default Conguration
• Conguration Notes: PFC and ETS in a DCB Map
• Conguring Priority-Based Flow Control
• Conguring Enhanced Transmission Selection
• Congure a DCBx Operation
• Verifying the DCB Conguration
• Performing PFC Using DSCP Bits Instead of 802.1p Bits
• PFC and ETS Conguration Examples
• Using PFC and ETS to Manage Data Center Trac
• Priority-Based Flow Control Using Dynamic Buer Method
• Conguring the Dynamic Buer Method
Enabling Data Center Bridging
Data center bridging supports converged enhanced Ethernet (CEE) in a data center network. By default, DCB is disabled. It must be
enabled to support CEE.
NOTE
: DCB is not supported on the Port Extender (PE) ports and cascade ports. For information about PE ports, see Interface
Types and Port Extenders.
• Priority-based ow control
• Enhanced transmission selection
• Data center bridging exchange protocol
• FCoE initialization protocol (FIP) snooping
DCB processes virtual local area network (VLAN)-tagged packets and dot1p priority values. Untagged packets are treated with a dot1p
priority of 0.
To enable DCB, enter the following command.
Enable DCB.
CONFIGURATION mode
dcb enable
By default, PFC is enabled for 2 lossless queues when use the dcb enable command. To congure, 3-4 lossless queues use the
following syntax:
Dell(conf)#dcb enable pfc-queues ?
<1-4> Number of PFC lossless queues(default=2)
11
Data Center Bridging (DCB) 263